Mayavadis are illusionists because they teach the philosophy of Maya
or Illusion.

They wrongly conclude that the manifestation of material nature [prakriti]
is only illusion and therefore false. However according to the philosophy of Bhagavad-gita
and Srimad-Bhagavatam, this is not so. The manifestation of the world is not accepted
as false; it is accepted as real, but temporary and occasional. This material
manifestation takes place at a certain interval, stays for a while and then disappears.

The creation and annihilation of the material world take place in terms of
the time factor, which is the unmanifested,
impersonal feature of the supreme Lord so much adored by impersonalist philosophers.
[see also: the three features of the Lord]

The material creation seems to be separated from the Lord as external energy
due to this time factor. This can be understood by the example of a tape recorder.
It is something like the tape recorded voice of a person who is now separated
from the voice. As the tape recording is situated on the tape, so the whole cosmic
manifestation is situated on the Lord's material energy and appears separate by
means of kala.

The Mayavadi illusionists do not know that the material nature [prakriti] is
ever existing in its subtle form [pradhana] as the energy of the Lord, but it
sometimes manifests this nonexistent or temporarily existent nature, the cosmos
[SB 3.26.9]. The material manifestation is therefore the objective manifestation
of the Supreme Lord

In Bhagavad-gita the Lord refers to this as 'my prakriti'. This prakriti consists
of the three modes of material nature: sattva-guna, raja-guna, tama-guna, which
stand for equilibrium, motion and inertia. The interaction of material nature
takes place when the equilibrium of the three gunas
is disturbed by the time factor. Therefore, kala or eternal time is the primeval
cause of the interactions of the three modes of material nature. Time creates,
time maintains, time destroys, and this time factor is non other than the Lord.

Mayavadi philosophers are, as a class, non-devotees since they dont believe
in the Personality of the Supreme Lord. Preaching impersonal atheistic philosophy,
they naturally are misled almost in all occasions. Vaishnavas, as well as all
theistic people, who share the common concept of a Supreme God, should beware
of this atheistic mayavadi poison, in as much as milk touched by the lips of a
serpent has poisonous effects.

Since the impersonal interpretation of the word theism already contradicts
the dictionary understanding, one can easily understand how such an interpretation
becomes the source of many arguments. Theo is God and God is the Supreme Person:
the one without an equal - with no one superior to Him. If the Supreme had no
personality, in some way He would already be less than all the thinking, feeling
and willing persons of His creation. This idea is unacceptable to a Vaisnava,
thus he cannot accept either Mayavada philosophy nor the Buddhist's or any other
Impersonalist's interpretations of the final truth.

The Mayavadi philosophy is "veiled Buddhism." In other words, the voidist
philosophy of Buddha is more or less repeated in the Mayavadi philosophy of impersonalism,
although the Mayavadi philosophy claims to be directed by the Vedic conclusions.
Lord Siva, however, admits that this philosophy is manufactured by him [in his
incarnation as Sankaracarya] in the age of Kali in order to mislead the atheists.

Sankaracarya rejected Buddha's philosophy, which gives no information concerning
the spirit soul. Buddha's philosophy deals only with the material
elements and the dissolution of matter. Generally they compare the living
entities to the bubbles of the ocean, which merge into the ocean; thus the goal
of Buddhism is to merge everything into the voidness. For impersonalists this
might be the highest perfection of spiritual existence attainable without individual
personality, but for a personalist to dissolve his individuality would amount
to "spiritual suicide".